Parallel protractor.



C. P. HAGER.

PARALLEL PROTRACTOR.

APPLICATION rILED JAN. zo, 1912.

Patented Jan. 28, 1913.

IIHIIIIHIIUIII smiles. r. Baena. oir-nano. Nirvana- MBALLEL .lnowmcroe mamario. of reuen mmf.

Bamnted Jan. 28,1913.

Appiioation-ledanuary 20; 1912. Seria] 140.372,284.

To all whom t may concern:

Be it knownthat I, GHARLES P; EAGEa, a citizen of the United' States, anda resident of Reno, in the countyo Washoe and State ofNevada, have invented" a new andf Improved Parallel; Protractor, of which the following is a full, clear, and exact descrlption.

This inventionk relates to protractors, particularly. to quick acting protractprs, and` has for an object the provision of 1me proved means whereby any angle may be quickly and accurately found.

Another object ofthe inventionI 1s the provision of' an improved structure 1n a protractor which will permit' the protrator to be adjusted for ormingparaliel" extensionsIA whereby lines` may be drawn several times the length oir the protractor whilere.- mainin in itsforiginalf-position. l

A sti l' further object of the invention 1s the provision andv arrangement of improved, means ,designedto engage theboardor pa,- per on whlch the,devicel is mounted, associated with movable means and a measuring indicator whereby the device? may be swung around` a given point and' causedi to occupy any desired angle .to its original osition, such angle being"` disclosed' onl the indicator.

Ih carryingr out the objects of the invention, a suitablebase isprovided; to the ed es of -which are secured' straight edges or ru es designed to be shifted; longitudinally ofl the body' forV permittinglinesfto be drawn bevond either'. end ofthebody without moving the device. Arran the'l body off the device isv a construction in# cluding a pin designed' to he pressed into the table or paper, for' acting as a fixed` pivot aroundwhich the device may be swung for securingan angle. In order to know what angle 1s being secured, a rotating traction device is provided, formed with an indicating mechanism so that the angle will be indicated.` thereon as.` the d'ef vice. is moved.

A practicalembodiment ofthe invention is represented in the accompanying draw which Similar Characters Qf rference. indjca te corresponding paritlsgina a l l the views.

mentfxoitheinvention-{Ii isia bottom` plan view o' the devices own' in' Fig. 1,

-able thurn f Vwhich are threadedl into the respective d; near one end of' ings-forming a part ofthis specification, in`

one of thestraight edges extending beyond oneend' of'thevb'ody ofthe device; Fig. 3 is a side View of the structure shown in Fig. l, the same being shown on an enlarged scale and certain parts broken away; Figf 4 is a section through Fig. 3 approximately on' the line 4 4; Fig. 5 is a section through Fig. 4 approximately on the line 5 5; and Fig. 6 is a section through Fig. 3 on the line 6'-6'..

Referring to the accompanying drawings by, numerals, 1, indicates a body formed of any .desired material,to which the various moving parts are connected. Arranged on each edge of the body 1 is a dovetailed groove in which. dovetailed tongues. 2 are -slidingly positioned, which are formed preferably integral w1th the straight edges 3 and whereby the straight edges are connected with the body 1, but. are permitted a free longitudinal movement. The upper and lower vsurfaces of the dovetailed tongues 2 are arranged parallel with the upper and lower surfaces 5 andA 6 of the ystraight edges 3 and 4 whereby the straight edgesQmayy be turned over whenever desired. This isiniportant-as it permits graduations.

'to beprovded on each side. of the lstraight E edges, and consequently four sets of graduations forlonlytiwo straightv edges. In order.

to properly. operate the straight edges, suitmelnbers 7 and 8 areprovidedj straight edges so as` to be` readily removed andlnserted" from the oppositeside when the straight edges areturnedover.

One end of the body 1 is provided with a lslot 9 havin acountersunk portion 10. Ar-

ranged to s ide in the slot 9 is a, post 11 threaded at 12 and bifurcated at its upper endifor receiving an eccentric lever 13. The post 11 is provided with a projecting Hange. 14 which [its into the countersunk portionV 10 in order to prevent the post from being :removed by an upward movement thereof. A nut 15 is screwed over the threads 12- for clamping the post 11 rigidlyl to the body 1, and a locking set screw 16 is mounted on the nut 15v for preventing the nut 15 from slipping or becoming dislocated. The post 11 1S provided` with a central bore 17, in

which isfitted a reciprocable pin 18 formed with a centrallboro forfreceivin'ga needle 1 9. Aset screw.v 201isV threaded into'k the pin 18, as shown in Fig. 5, for clamping the needle as for instance by screws.

19 ri 'dlv into place. The needle 19 is designe to continually project a short distance below the bot-tom of thepin 18 so as to enter or pierce the paper on which the device is mounted, while the pin 18 merely presses against the paper. Upon a downward movement of the handle 2l of the lever 13, the pin 18 will be depressed until the needle 19 has entered the paper and any further movement of the handle 21 will canse the end 22 of the device to be raised and consequently cause a traction roller 23 to become disengaged from the paper. The raising of the end 22 will not raise the roller 24 or the end 25. When the end 22 has been raised, the end 25 may be swung around in the arc of a circle or for a complete circle, as desired, as hereinafter described.

Secured to the body 1 are supports 2G and 27 formed preferably in two parts and secured to the body 1 in any desired manner, The parts of the supports 26 and 27 are clamped together by screws or bolts 28 and 29 so as to firmly clamp journal pins 30 and 31. Each of these journal pins is formed with a conical end fitting in a conical socket in a shaft 32, The shaft 32 has rigidly secured thereto the traction rollers 23 'and 24, and is protected by a suitable housing 33 secured to the body 1 in any desired manner. The traction rollers 23 and 24 are preferably corrugated or slightly cogged so that the same will positively turn when moved over the paper or other surface on which the device is being moved. Connected to the shaft- 32 in the center or at any other desired point, is a beveled gear 34 which meshes with a beveled gear 35. The beveled gear 34 is held in place by a spring 36 and may be adjusted for any desired position. The beveled gear 35 is rigidly connected with a shaft 37 which is mounted in a bearing 38. Rigidly connected to the upper end of the shaft 37 is a support-ing block 38 which has connected therewith 'an indicating arrow 39 which is adapted to move over the graduations 40 of a dial 41.

In operation when it is desired to draw a line at a certain angle from a given line, say at an angle of 20, one edge of the protractor is placed parallel with the given line and then t-he handle 21 depressed so that the needle 19 will enter the paper and the pin 18 will cause the end 22 of the protractor to rise. The end 25 is then grasped and moved pivotally until the dial 41 indicates that the device has swung around 20. The handle 21 is then raised until the pin 18 and needle 19 have become disengaged from the paper. After this the entire device is pushed toward the given line in substantially a direction opposite to that which the device has just previously traveled. The device is pushed until the edge thereof has reached any particular point from which it is desired to extend the 20 angle.

In order to test the device so as to be positive that the same is correct, thc lever is depressed as above described after a line has been previously drawn parallel with the center of the straight edges, and then the device swung around for a complete circle. lVhen the dial 41 indicates that the device has traveled 360, if the straight edge is correctly positioned against the line originally drawn, then the device is correct. If the straight edge has passed the line originally drawn the nut 15 is loosened and the post 11 moved longitudinally in the slot 9 in a direction away from the end 25. This will cause the roller 24 to travel in a larger circle. After the device has been again tested, the post 11 may be again adjusted, and so on until the device is absolutely correct.

Having thus described my invention, lI claim as new and desire to secure by Letters Patent z- 1. In a protractor, a body portion, ,a pair of traction wheels therefor formed with corrugations on their peripheries for preventing slipping, a reciprocable pivotal pin mounted on one end of said body portion, a cam pivotally connected with said body portion and engaging said pin for pressing on the top thereof, said cam being of such a size as to cause said pin to project below said body portion and raise the end of the body portion carrying said pin whereby the opposite end of said body portion may be swung around through any desired angle, and means operated by the traction Wheels near the end opposite said in for indicating the number of degrees sald body portion has been swung.

2. In a protractor, a body portion, a pivotal pin arranged near one end of said body portion, means for raising said pivotal pin, and for lowering the same to such an extent as to cause an elevation of the end of the protractor, a traction wheel arranged at the opposite end of said body \portion to said pivotal pin, and indicating means associated and co-acting with said traction wheel for indicating the angle through which the protractor has been moved when the same has been swung on `said pivotal pm.

3. In a protractor, a body portion, a reciprocable pivotal pin, means mounted on said body portion and engaging said reciprocable pivotal pin for forcing the pivotal pin downward and the ends of said body ortion upward, a traction wheel arrange at the opposite end of said body portion to said pivotal pin, a shaft. rigidly secured to said traction wheel, an indicating member, and means for connecting said in` dicating member and said shaft, whereby when the protractor is moved pivotally will rotate and said indicating member will 'be moved.

4. In a protractor, a body portion formed with a slot in one end, a post mounted in said slot, means for clamping said post to said body portion at any point along said slot whereby the distance of the post from the opposite end of said body portion may be varled, a reciprocable pivotal pin mounted in said post, a pivotally mounted lever structure engagin said pin and forcing the same downwar and the end of said body ortion upward, a traction wheel arranged) at the opposite end of said body portion to said sl'ot, and an indicator connected with said traction wheel for indicating the degree of rotation of said body portion around said' pivotal pin.

5. In a protractor, a body portion, a -pivotal pin, means for simultaneously forcing the pin downward and the end of the body portlon upward, a traction wheel arranged at each end of said body portion, the traction whel at the end in which the pivotal pin is mounted being raised when said end has been raised, a shaft for rigidly connecting said traction wheels, an indicating arm, and means for operatively connecting said indicating arm with said shaft whereby said indicating arm is rotated at a. certain ratio to rotation of said traction wheel lnounted at the end of said body portion opposite said pivotal pin, said pivotal, pin bein 'adapted to be raised and said body portlon moved bodily laterally with both wheels in engagement with the supporting surface when it is desired to draw a line at an angle to a' given line.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES P. 'EAGER Witnesses: l

MA'rrHEw KYLE,

S. W. GooDALE. 

